1. Field of the Disclosure
This application generally relates to automatic setting of arms in a trim removal or stacking device, and other matters.
2. Background of the Disclosure
Sheet fed production lines generally operate on substantially flat sheets that are relatively thin with respect to their width, such as paper, cardboard, corrugated cardboard, thin plastics, thin wooden boards, and other materials. For example, the sheets might flow through a rotary die cutter (RDC), which perforates or semi-perforates the sheets. The cut sheets might flow through a stacker, which helps remove any excess pieces (sometimes known as “trim removal”), separates the sheets into separate flows, and stacks and possibly binds them for transport.
It sometimes occurs that it is desirable to separate the sheets into separate streams, such as spreading them out horizontally, after they exit the stacker. For example, as the sheets undergo trim removal, they also can be separated into streams with distinct interstitial distance. This can be usefully performed in the trim removal section, which captures the sheets as they flow from the rotary die cutter, and which includes multiple arms (sometimes known as “trim arms”) that can be adjusted to separate the sheets as trim is removed.
Some known systems provide for manual adjustment of trim arms, such as by an operator of the device. One or more operators might set each arm in position to support and capture the sheets, and to adjust their angle of travel with the effect of separating them into individual streams. This process is inefficient. Further, it sometimes occurs that the operators misalign the trim arms, with the effect that the trim arms can fail to support the sheets, fail to adequately control the sheets, or fail to accurately separate the sheets.
Other known systems provide for support and trim removal in a first section of the flow, and separation of the sheets into distinct streams in a second section of the flow. In such systems, the second section would be separately adjusted, with the effect that a separate section, such as an incline conveyor, is involved with adjusting the angle of travel of the sheets. It sometimes occurs that the length of the separate section (such as the incline conveyor) can be inconvenient or pose undesirable or excessive draw on available space.
Other known systems provide for separate adjustment of each end of the trim arms, offsetting them to provide a skew that adjusts the angle of travel of the sheets. In such systems, this can involve two separate mechanisms to find both ends of each arm and to offset them properly. It sometimes occurs that these systems are slower and less reliable.
Each of these examples, as well as other possible considerations, can cause difficulty in aspects of a skewing function being applied to separate the sheets (such as in a trim removal section), particularly in those cases in which careful alignment is desired, or in those cases in which changes of alignment are desired. Similarly, each of these examples, as well as other possible considerations, can cause difficulty in aspects of an automatic trim arm setting system, particularly in those cases in which there is an advantage to maintaining the flexibility of adjusting alignment, and the relatively reduced expense of stopping the flow to make adjustments.